Ultrasound assessment of bladder volume: is it valid after delivery?

AIM: To assess the validity of a commercially available bladder volume scanner in the puerperium.

METHODS

A prospective blinded comparison of bladder volume measurement after vaginal delivery using the BladderScan bladder volume instrument (BVI) 3000 and Foley catheter; comparison using the intraclass correlation coefficient.

RESULTS

The mean difference between the two measurements was a 130-mL over-measurement by the bladder scanner (range: -156 mL to +422 mL). The intraclass correlation coefficient was 0.23 (95% confidence interval 0.00, 0.59).

CONCLUSIONS

The BladderScan BVI 3000 is not an accurate instrument to assess bladder volume the day after vaginal delivery. Some of the discrepancy might relate to use of the Foley catheter as the reference standard. Further comparison between the BladderScan and a short female catheter or real time ultrasound is indicated.